how to tcpdump traffic from a specific kubernetes pod

get_pod_interface.sh

#!/bin/bash -eu

POD_NAME="$1"

IFACE="$(kubectl exec -t "$POD_NAME" -- bash -c "cat /sys/class/net/eth0/iflink")"
echo "Internal interface index: $IFACE. Searching for it on host..."                   
for i in /sys/class/net/veth*/ifindex; do                                                  
    if grep "$IFACE" <$i >/dev/null; then
        echo -n "Host interface: "
        echo "$i" | grep -o -E "veth[^/]*"
    fi                                                                                 
done

usage.md

Example usage

$ ./get_pod_interface.sh my-pod
Internal interface index: 281. Searching for it on host...
Host interface: veth0f6a8d6

$ sudo tcpdump -i veth0f6a8d6 port 80